The present invention relates to a gas rinsing or scavenging apparatus for use in a metallurgical vessel containing molten metal, particularly an induction furnace, the apparatus being of the type including a frusto-conical refractory inner scavenging cone or block embedded in and extending through the refractory lining of the metallurgical vessel, the inner scavenging block having a smaller end surface facing the molten metal within the vessel and a larger base end directed away from the molten metal, whereby a scavenging gas to be supplied to the molten metal is passed through the inner scavenging block from the outer larger base end to the inner smaller end surface.
An apparatus of this type is described in the journal "Giesserei 72", 1985, No. 6, pages 133-136. In this apparatus the scavenging block rests on coarse tamping clay or a stamping mass. During operation the scavenging block becomes eroded and must be replaced, and when this is necessary the tamping clay also must be replaced. This is a complicated and time consuming operation.
West German DE-OS 32 40 097 discloses an arrangement wherein the scavenging block is provided with an insert of a filler material having a melting point below the temperature of the molten metal within the vessel. When the scavenging block becomes eroded to a point such that the molten metal within the vessel progresses to the filler material insert, such insert melts, thereby forming a seal which prevents the molten metal from the vessel from breaking through the scavenging block. A disadvantage of this arrangement however is that once this occurs, then it no longer is possible to supply the rinsing or scavenging gas through the scavenging block to the molten metal within the vessel.